FUNGUS-INFECTED SEEDCORN MAGGOT FLIES
FUNGUS-INFECTED FLIES, Hylema platura (Meigen), Anthomyiidae, DIPTERA
maggot flies are greyish-brown and about one fifth inch long. The legs are
black and there are bristles scattered on the body. Flies that are infested
with Entomophthora fungi
become bound to twigs, leaves, wires and other objects by the mouthparts. Infected flies
are swollen and have pinkish bands on the abdomen. Sometimes gray Entomophthora
spores are visible on the fly and on the substrate nearby. Seedcorn maggot
eggs are tiny and white and have a coarse surface when viewed through a microscope. The
white to creamy maggot grows to 1/4 inch long. It is legless and pointed at the
head. The last larval skin hardens to form a dark brown, capsule-like puparium
about 3/16 inch long.
Most of the life cycle is spent in the soil of various field crops in the maggot stage. Flies emerge in May and deposit their eggs in soil where there is an abundance of decaying vegetable matter or seeds and young plants. The maggots hatch and burrow into seeds, often destroying the germ. They soon develop into puparia in the soil and in 12 to 15 days a new generation of adults emerges. There are three to five generations each year.
Some seedcorn maggot flies become infected with a fungus in the genus Entomophthora. This fungus apparently causes the flies to land on protruding objects such as any dead twigs of dogwood, crape myrtle, clothes lines, and fence posts. The flies cling there and usually die in the afternoon as their abdomens swell with fungal strands inside. Early the next morning, the fungal spores are released into the air while the humidity is high. The spores infest other seedcorn maggots. The dead flies shrivel and eventually fall from the twigs.
Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by the North Carolina Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical. For assistance, contact an agent of the North Carolina Cooperative Extension Service in your county.
© 2001 NC Cooperative Extension Service
Web page last reviewed January, 2011 by the webperson.